Current selection guideline for CRT uses broad QRS duration (>120 ms) as a marker for ventricular dyssynchrony. However, more recent data supports mechanical marker specifically measured by Tissue Doppler Imaging (TDI) as a better criterion to predict response to CRT. Sixty seven patients with significant left ventricular dysfunction (EF less than 40%) and narrow QRS complex were prospectively enrolled. They underwent Tissue Doppler Imaging (TDI) study to evaluate intraventricular mechanical dyssynchrony. Dyssynchrony index which is defined as standard deviation of time to peak systolic velocity in twelve ventricular segments was measured. A value greater than 32.6 is taken to reflect significant ventricular dyssynchrony. Overall 38 patients (56.7%) demonstrated significant dyssynchrony. There was no significant correlation between QRS duration and the Ts-SD-12 (r = 0.14, p = 0.11). Ventricular mechanical dyssynchrony is common in patients with normal QRS duration. Therefore, QRS duration alone will miss a substantial proportion of suitable patients for CRT and therefore deny them this adjunct therapy. We propose echocardiographic parameters, specifically TDI, to be included in patient selection criteria for CRT.

Background: Astrocytic gliomas are the most common primary brain tumors that developed from glial origin. The angiogenic cell population from brain tumor enhances the recruitment of circulating cancer stem cells homing towards tumor site. Objectives: This study aimed to investigate the tumor angiogenic cell population that stained with CD133+ and VEGFA+ markers and its association with circulating cancer stem cell (CD133+/VEGFR2-) population in the peripheral blood mononuclear cells (PBMCs) of astrocytic glioma patients.Methods: A total of 22 astrocytic glioma patients from Hospital Universiti Sains Malaysia who consented to the study were included. Tumors (n=22) were sliced and stained with CD133+ and VEGFA+ angiogenic markers and counter stained with DAPI. The circulating cancer stem cells (CD133+/VEGFR2-) in PBMCs (n=22) were quantified using FACS based on the expression of CD133 and VEGFR2 markers. The paired t-test and Pearson correlation were used for the data analysis.Results: The percentage of angiogenic cell population was significantly higher in brain tumor compared to adjacent normal brain tissue (1.25 ± 0.96% vs. 0.74 ± 0.68%; paired t-test=2.855; df=21, p = 0.009). Positive correlation was found between the angiogenic cells of brain tumor tissue and adjacent normal brain tissue (Pearson correlation, r = 0.53, p = 0.011). Significant positive correlation was found between angiogenic cells in glioma tumor and cancer stem cells in peripheral circulating systems of astrocytic glioma patients (Pearson correlation, r = 0.42, p = 0.049).Conclusion: Angiogenic cells in the brain tumor resident promote the recruitment of circulating cancer stem cells homing to the tumor site and induce the proliferation and growth of the tumor in astrocytic glioma patients.